Research and prospect of flexible forming theory and technology of hollow shaft by three‑roll skew rolling

With the rapid development of high-end equipment in aviation, high-speed rail, and other fields, the requirements for the necessary shaft foundation parts on the equipment are more stringent. This has resulted in rapid development of the new generation of three-roll skew rolling (TRSR) flexible forming shaft part technology. It is an important issue to explore the theory and technology of TRSR flexible forming of hollow shaft and systematically expounding the flexible forming theory of TRSR of hollow axle. Therefore, this paper explores the feasibility of TRSR through the combination of theory and experiment and analyzes the formation mechanism as well as develop macro and micro uniformity law in order to clarify the quality control measures. In order to realize the low-cost forming of hollow axle with short process, the piercing-rolling compound forming (integrated forming of shape and inner hole of hollow axle) and the multi-roll skew tandem rolling technology for large section shrinkage shafts are innovated. The forming mechanism is verified through the simulation research. Based on the abovementioned research, it is concluded that skew-rolling composite integrated forming of large hollow shafts, multi-roll skew tandem rolling technology for large section shrinkage shafts, and the flexible forming process and equipment of digital TRSR is the future development direction of the TRSR flexible forming technology of hollow shaft. The results provide a theoretical basis and development direction for improving the precision short process, high efficiency, and high-quality manufacturing of high-end equipment shaft foundation.